Predicting Risk for Recurrence of Supraventricular Tachycardia in Infancy

Infants with supraventricular tachycardia (SVT) and an early diagnosis of disease, without the presence of Wolff-Parkinson-White (WPW) syndrome, who are discharged on first-line monotherapy are at the lowest risk for recurrence. These findings were published in the Journal of the American College of Cardiology.

Recognizing that the ability to predict recurrence risk in infants with SVT could modify current management paradigms and guide future care, researchers sought to evaluate the incidence of and the factors associated with SVT recurrence in infancy. They conducted a single-center, retrospective study between 1984 and 2020, with a prospective telephone interview follow-up to determine longer-term SVT recurrence.

The primary study outcomes included age at initial presentation of SVT, incidence and timing of SVT recurrence, and risk factors associated with SVT recurrence. A secondary study outcome was to determine whether certain infants have a lower risk for SVT recurrence and thus may be responsive to a shorter duration of antiarrhythmic treatment.

A total of 460 infants were evaluated, of whom 87% were diagnosed with SVT when they were aged 60 days or younger (median, 13 days; IQR, 1-31 days). Overall, 62% of the participants were male. During a median follow-up of 5.2 years (IQR, 1.8-11.2 years), 33% of the patients experienced an SVT recurrence.

Per multivariable analysis, the factors associated with SVT recurrence included the following:

• Fetal diagnosis (hazard ratio [HR], 1.90; 95% CI, 1.26-2.86; P =.002)
• Late (>60 days) diagnosis (HR, 1.73; 95% CI, 1.07-2.77; P =.024)
• WPW syndrome (HR, 2.46; 95% CI, 1.75-3.45; P <.0001)
• Need for multiantiarrhythmic or second-line therapy (HR, 2.08; 95% CI, 1.45-2.99; P <.0001)

According to a classification and regression tree analysis, WPW was associated with the highest risk for recurrence. Among those without WPW, age at diagnosis was the most important factor predictive of SVT recurrence risk. A fetal diagnosis or a late diagnosis incurred a higher risk. If multiantiarrhythmic or second-line therapy was also needed, the risk almost doubled. Infants without WPW who were diagnosed early (0-60 days of age) and were discharged on propranolol were at the lowest risk for SVT recurrence.

The study has several limitations, including that it is a retrospective analysis design limited to a single tertiary center. This may over-represent recalcitrant cases of SVT. Further, lack of follow-up or follow-up outside of the center in which the study was conducted might limit the ability of the researchers to obtain accurate data.

The investigators wrote, “These findings raise the possibility that this subgroup of infants may be amenable to earlier discontinuation of antiarrhythmic therapy.”

Disclosure: One of the study authors has declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of the author’s disclosures.